WALKERS and nature enthusiasts are being urged to keep watch on ash trees in Sherborne for signs of the feared dieback disease.
It is caused by the fungus Chalara fraxinea and was found in the UK for the first time earlier this year.
Dorset County Council has issued an alert – although the disease has not yet been found in the wild, young ash plants in tree nurseries and recently-planted sites elsewhere have been found to be infected and the fungus spores are carried by the wind, so the chance of the disease spreading is high. Symptoms include the premature loss of leaves from the outer parts of the crown – top and sides – and long, diamond-shaped lesions or areas of sunken and discoloured bark on twigs.
These lesions girdle twigs and small branches, starving the leaves of nutrients and causing whole branches to die. In mature trees, it is new growth that is affected.
The county council has asked residents to report any suspected cases as quickly as possible.
The council's arboricultural manager, Steve Maros, said: "It's important that people are aware of ash dieback, which is now one of many pests and diseases that pose a threat to our native woods and trees, but there is currently no need for the preventative destruction of ash trees.
"There is also no reason that some ash trees can't continue to be planted as some varieties are more tolerant of the infection, but people should buy from local, reputable retailers."
For information, see www.dorsetforyou.com/ash-dieback-disease.